Watch movement safety lock



May 4, 1954 H. w. FISHER 2,677,229

WATCH MOVEMENT SAFETY LOCK Filed July 21, 1953 IN V EN TOR.

Patented May 4, 1954 UNITED STATES PATENT OFFICE.

4 Claims.

My invention relates to improvements in the attachment of a threaded cover plate to a watch body in order to prevent locking thereof.

An important object of my invention is to provide loosening washer means made of soft material loosely and rotatably confined within the cover of a watchcase which is threaded onto the case itself to permit removal or assembly and to prevent the screws securing the watch work mechanism, or the movement, from digging and looking into the case cover element when the screws become slightly loosened by virtue of the actuation of the stem of the watch during the frequent winding and setting operations.

Another object of my invention is to provide an element, or a loosening washer, consisting of a soft material permitting the sharp points of the heads of the retaining screws which retain the movement to dig thereinto when loosened or freed rather than normally digging into the inner surface of the watchcase cover proper thus preventing the removal thereof from the watchcase.

Another object of my invention is to provide a loosening washer consisting of an annular element made of soft material such as soft metal, or plastic, or plastic composition, and which has sufficient tenacity so as to maintain rigidity and permit rotational movement within its confines in the assembled watchcase whenever an attaching screw should dig into it.

A still further object of my invention is to provide an element of the aforementioned character which is simple in construction, inexpensive to produce. hence can be economically manufactured in quantity production.

Other objects and ancillary advantages inherent in my invention will become apparent from an examination of the accompanying drawings, bearing further elucidation in the ensuing description, in which:

Fig. 1 is a top view of my invention shown in position in a watchcase illustrated in phantom.

Fig. 2 is a cross-sectional view taken, substantially, on the lines 2-2 of Fig. 1.

Fig. 3 is a fragmentary cross-sectional view showing the damage attendant to a watchcase cover when my invention is not utilized.

Fig. 4 is a cross-sectional view of my invention.

Referring to the various views, a watchcase is generally designated 6, and consists of a watchcase body and a cover M; the cover It being provided with a threaded portion ll engaging the reduced threaded extension [8 on the watchcase 20.

Usually approximately two or three very fine pitched threads are provided for securing the watchcase cover M to the watchcase 20. The movement designated 1 and 8 is usually secured to the watchcase 20 and confined therein by means of two or more holding screws designated 9 and Hi.

It will be noted that those screws are of the fillister head type and have rather sharp edges and corners at the slot, which, when the screws are loosened, will dig into the watchcase cover l4 looking it against rotation and making it very difiicult to remove the watchcase cover I4 from the watchcase 20 without damage when access thereto is required for repair or adjustment purposes.

In Fig. 3 I illustrate the attaching screw 9 which shows how it has loosened within its confines and its head has dug into the inner surface of the watchcase cover forming a dent l3 so that it becomes difiicult and almost impossible to remove the cover I4 without damage.

It will be noted in Figs. 1 and 2 where my invention is generally designated 5, it is rotatably held in place within the confines of the recess I6 of the watchcase cover l4 so that it is free to rotate therein; it will be also noted that the screw in is properly seated, whereas the screw 9 has been partially unseated and its sharp edges in the slot or the peripheral portion of the head have dug into and formed a dent IS in the loosening washer, generally designated 5. This washer consists of an annular ring or body which is made of plastic material, or soft metal, designated H and having an opening I2 therein so that the annular or coronal area thereof will lie within the radial ambit of the position of the lockscrews or holding screws, 9 and I0.

Thus, when the screw 9 as shown in Fig. 2 cuts into the loosening washer 5, it will permit the watchcase cover M to be rotated, the washer slipping rotatably within its confines, being engaged at the dent i5 and driven circularly and thus permit disengagement of the thread, I! from the reduced threaded extension l8, permitting removal of the cover and access to the watch movements I, 8 without damaging the cover or the watch.

The screws 9 and I0 become loosened from time to time when the winding stem contained within the bearing 19 is utilized for winding and setting the watch.

While the invention has been herein described in its preferred form it is to be understood that it is not limited to the specific construction herein shown and that it may be practiced in other 3 forms without departin from the spirit and scope thereof.

Having thus described and revealed my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a watch having a watchcase and a watchcase cover provided with a recessed portion and threadably and removably secured to the said watchcase, a movement secured to the said watchcase, and screws securing the said movement in assembly; anti-locking means loosely and rotatably confined in the said recessed portion and in intimate contacting relationship with the said screws to prevent the said screws when loosened from locking the said watchcase cover to the said watchcase.

2. In a watch having a watchcase and a watchcase cover provided with a recessed portion and threadably and removably secured to the said w'atchcase, a movement to the watchcase, and screws securing the said movement in assembly; anti-locking means made of soft material and loosely and rotatably confined in the said recessed portion and in intimate contacting relationship with the said screws to prevent the said screws when loosened from locking the said watchcase cover to the said watchcase.

said

3. In a watch having a watchcase and a watchcase cover provided with a recessed portion and threadably and removably secured to the said watchcase, a movement secured to the said watchcase, and screws securing the said movement in assembly; anti-locking means loosely and rotatably confined in the said recessed portion and in intimate contacting relationship with the said screws to prevent the said screws when loosened from locking the said watchcase cover to the said watchcase, the said anti-locking means being of coronal geometrical configuration.

4. In a watch having a watchcase and a watchcase cover provided with a recessed portion and threadably and removably secured to the said watchcase, a movement secured to the said watchcase, and screws securing the said movement in assembly; anti-locking means made of soft material and loosely and rotatably confined in the said recessed portion and in intimate contacting relationship with the said screws to prevent the said screws when loosened from locking the said watchcase cover to the said watchcase, the said anti-locking means being of coronal geometrical configuration.

No references cited. 

